Hydraulic shock absorder structure



prll 20, 1943. R H wHlsLER, JR 2,316,924

HYDRAULIC SHOCK ABSOBBER STRUCTURE Filed Nov. 12, 1941- y F l FIGJ.

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RALPH H.WHISLER JR.

ATTORNEYS Patented Apr. 20, 1943 HYDRAULIC SHOCK ABSORBER STRUCTURE Ralph H. Whisler, Jr., Monroe, Mich., assigner kto Monroe Auto Equipment Company, 'Monroe Mich., a corporation of Michigan Application November 12, 1941, Serial No. 418.791

( Cl. 18S-88) 8 Claims.

This invention relates generally to hydraulic shock absorbers and refers more particularly to an improved piston and valve assembly for use in a hydraulic shock absorber of the direct acting type.

One of the essential objects of the invention is to provide a piston and valve assembly wherein the passages through the piston, and the valves controlling said passages are constructed and arranged in such a way that sufcientpressure to open the valves for said passages may be built up faster by a shorter stroke of the piston in the pressure cylinder.

Another object is to provide a piston construction wherein the passages for the hydraulic medium are constructed and arranged in such a way that the displacement of hydraulic medium upwardly through the piston on the compression stroke thereof is substantially equal to the full cross sectional area or bore of the pressure cylinder. g

Another object is to provide a piston and valve assembly wherein the passages for the hydraulic medium are arranged in such a way in the piston that solid valves may be employed at the top and bottom of the piston to provide the desired resistance to the iiow of the hydraulic medium through the piston. In my present invention the piston contains two sets of open ended inclined passages. One set inclincs from a large diameter circle on the bottom f the piston to a small diameter circle on the top of the piston. The other set inclines from a large-diameter circle on the top of the piston to a small diameter circle on the bottom of the piston. open ends of the passages at the small diameter circles at the top and bottom .of the piston and 'thus are inside and clear of the large diameter circles of open ends of said passages at the topand bottom of the piston.

Another object is to provide a piston and valve assembly that is simple in construction, inexpensive to manufacture and eicient in operation.

Other objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing, wherein:

Figure l is a longitudinal through a shock absorber having a piston struciure embodying my invention;

Figure 2 is a sectional view through the piston per se:

Figure 3 is a plan view of the piston illustrated in Figure 2.

The valves control the :n

sectional view the piston embodying my Referring now to the drawing, A is the pressure cylinder. B is the reserve chamber, and C invention of a hydraulic shock absorber.`

As shown, the pressure cylinder A has a closure IIJ at its upper end apertured to receive a rod D for the piston C andKhas a base compression valve assembly il at its lower end.v The closure l0 carries asuitable seal I2 to prevent leakage of the hydraulic medium along the rod to the exterior of the shock absorber, while the base compression valve assembly Il has a body I3 Arigid with lthe cylinder A and' provided with a relatively large central opening I4 and a series of smaller openings l5 substantially concentric with the central opening. a spring pressed disc valve I6 controlling the central opening i4, and a laminated spring valve l1 controlling the smaller openings I5.

The reserve chamber B is substantially concentric with the pressurevcylinder A and is mounted on an annular enlargement I8 of the closure ID. The lower end I9 of the reserve chamber B is closed and is rigid with a circular head E adapted to' be attached to the unsprung Weight of a vehicle. A similar headF is rigid with the outer end of the rod D and is adapted to be attached to the sprung weight of the vehicle.

The piston C is anchored on a reduced lower end portion of the rod D between a shoulder 20' thereof and a suitable retaining nut G and slidably engages the inner walls of the pressure cylinder A.- In the present instance. the piston C comprises a relatively thick annular body provided with beveled or inclined upper and lower edges 2| and 22. respectively, and having two sets of open-ended equally spaced passages 23 and 24. respectively. extending therethrough. The passages 23 incline upwardly from the flat lower face 25 of the piston to the upper beveled edges 2|. while the passages 24 cross the passages 23 and incline downwardly from the fiat upper face 26 of the piston to the lower beveled edges 22. Thus, the upper ends of the passages 23 are in a large circle concentric with the center oil the piston while the lower ends of said mss-ages arc in a smaller circle concentric with the center of the piston. The reverse is true of :he passages 24. Located between the top of the piston C and the shoulder 20' of the rod D is a laminated spring valve 30 that normally closes the upper ends of the passages 24, while between the underside of the piston and the retaining nut G is a laminated spring valve 3l that normally closes the lower ends of the passages 23.

In use, when the piston C is moving downwardly in the cylinder A on its compression stroke toward the base compression valve as sembly Il, hydraulic medium in the lower portion of the cylinder A below said piston will ow upwardly through the passages 24 in the piston past the upper laminated spring valve 3D to the space within the cylinder A above the piston.

Likewise, onthe compression stroke hydraulicY l medium will flow downwardly from the lower portion of the cylinder A through the openings I5 in the body I3 of the base compression valve assembly past the laminated spring valve AIl to the reserve chamber B. On the rebound stroke, the piston C will move upwardly in the cylinder A toward the closure I0; hence, hydraulic medium will flow downwardly through the passages 23 in the piston past the laminated spring valve 3l to the space in the cylinder below the piston. Likewise, on the rebound stroke of the piston, hydraulic medium will now upwardly from the reserve chamber B through the central opening sistance provided by theA piston compression valve 30 and the base compression valve I1.

Moreover, this laminated spring valve I1 must have higher unit pressure than the piston valve 30 to prevent starving the upper part of the pressure cylinder A of the hydraulic medium. As a result of the crossed openings 23 and 24, a full'bore displacement is obtained. Thus, it is possible to build up fasterV ina shorter stroke of the piston sulcient pressure to open the valves 30 and 3|. V

What I claim as my invention is:

l. In a shock absorber, a pressure cylinder, and.

a piston slidably engaging the inner walls of the cylinder and having a solid body containing two sets of open-ended passages and having-substantially flat top Vand bottom sides provided With beveled edges, one set of open-ended passages inclining upwardly from the fiat lower side to the beveled upper edges of said body, andthe other set of open-ended passages crossing the rst mentioned set of passages and inclining downwardly from the ilat upper side to the beveled lower edges of said body.

2. In a shock absorber, a pressure cylinder,

kand a piston slidably engaging the inner walls of the cylinder and having two sets of openended passages and 'substantially flat top and bottom sides provided with beveled edges, one set of passages extending from the at bottom side to the upper beveled edge of the piston, the second set of passages extending from the flat top side to the lower beveled edge of the piston, and laminated spring valves respectively on the ilat top and bottom sides of the piston, the valve on the top side of the piston controlling the upper open ends of one set of passages, the valve on the bottom side ofthe piston controlling the lower open ends of the other set of passages.

3. In a shock absorber, a pressure cylinder, and a piston slidably engaging the inner walls of said cylinder and comprising a solid body containing two sets of open-ended passages, each set inclining'from a large diameter circle on one side to a smaller diameter circle on the other side oi saidbody.

4. In a shock absorber, a pressurecylinder, and a piston slidably engaging vthe `inner walls of said cylinder and comprising a solid body containing two sets of open-ended passages, each set inclining from a large diameter circle on one side to a smaller diameter circle on the other side of said body, and valves upon the sides mentioned of the body. controlling the open ends of the passages Vat the small diameter circles, the open ends of the passages at the large diameter circles being outside and always free of said valves.

5. In a shock absorber, a pressure' cylinder. and a piston slidably engaging the inner walls of said cylinder and comprising a solid body containing two sets of open-ended passages, one set inclining fromla large diameter circle at the bottom to a smaller diameter circle at the top of said body, the other setinclining from a small diameter circle at the bottom'to a larger diam- /V eter circle at the top of said body, and solid valves clamped against the top and bottom of the body and controlling the open ends of the passages in the smaller diameter circles, the open ends of the passages in the larger diameter circles being outside and free of said valves.

6. Ina shock absorber, apressure cylinder, and a pistorrslidably engagingthe inner walls of the cylinder and comprising a solid body having crossed diagonally extending passages opening through both the top and bottom sides thereof, the openings provided by said passages in the top and bottom sides of said body being in inner and outer substantially concentric circles, and

solid valves clamped against'said top and bottom sides of the body and normally closing the openings in the inner circles, the openings in the' outer circles being outside and free of said valves.

'7. In a shock absorber, a pressure cylinder, and a piston slidably engaging the inner` walls of the cylinder and having two sets of open- `ended passages, one set crossing the other, the

open ends of said crossed passages being in` circles of different diameter at the top and bottom sides of the piston, and solid valves on the top and bottom sides of said pistonv normally closing the ends' of the passages in the circles of smallest diameter and being inside andffreeof the ends of the passages in the` circles of greatest diameter.

and a solid piston within and slidably engaging said cylinder, said piston containing two sets of open ended inclined passages, one set incliningr from a large diameter circle on the bottom of the piston to a small diameter circle/on the top of the piston, theother set inclining from a large diameter circle on the top of the pistonrto va small diameter circle on the bottom of the piston, and

disc valves clamped against the top and bottom of said piston at the center thereof. and normally closing the open ends of the passages at the' small diameter circles on the top and bottom ofl theV piston, said disc Ivalves being wholly inside and clear of the large diameter circles ol open ends of said passages at the top and bottoni of said piston.

RALPH H. WHISLER- JR.

8. In a shock' absorber, a pressure cylinder, 

